1. Field of the Invention
The present invention relates to keyboards. Such keyboards may be used with any machines for communicating, storing, processing or retrieving representatives of information, such as telegraphs, typewriters, type composing machines, cyphering machines, calculators and computers. Such a keyboard is particularly suitable for use with modern types of computers having visual display units and full screen editing facilities. Such computers are being increasingly used by originators of information without the intervention of specialist keyboard operators.
2. Description of the Prior Art
When the typewriter became a commercial success in the 1890's after a long history of experiment, a variety of mechanisms and keyboard layouts were in use. Some machines used the type-bar mechanism which later became universal for wholly mechanical typewriters. Because the early type-bar mechanisms were liable to jam if adjacent keys were struck in quick succession, the letters were arranged on the keyboard to avoid such sequences. The resulting so-called "Universal" keyboard, now generally known as QWERTY from its letter sequence, is inefficient in human terms, as only 50% of letters struck lie on the most used row, and the fingers must make many reaches to the other rows. Machines having type-wheel or type-sector mechanisms were able to use the somewhat better `Ideal` arrangement, having on one row the ten most frequent letters accounting for 70% of letters struck. Nevertheless, the type-bar mechanism proved more effective overall and it gained a large share of the market. A common standard keyboard layout proved a commercial necessity, and the `Ideal` and other minority layouts fell out of use even though with detailed mechanical improvements type-bar jams ceased to be a problem.
The QWERTY layout originated in the United States. With minor modifications it has become the standard for all languages written with the Latin alphabet. A few gross differences in letter frequency have been accommodated, and each nationality has made some special provision for accents, diphthongs and letters not used in English. The 20 or so European languages written with essentially the Latin alphabet require a total of some 11 accents and 8 additional letters or diphthongs. Printer's work requires a variety of special marks in addition to normal punctuation. Particular subjects may require the Greek alphabet, chemical symbols or other extensions of the character set.
An ordinary typewriter keyboard providing the Latin alphabet, the numbers, a limited set of punctuation marks and special symbols, and a few machine control functions has some 46 keys. With the advent of electronic computers the QWERTY keyboard has been enlarged by the addition of a ten key numerical keypad as used on calculators, duplicating the ten numeric keys on the top row of the typewriter layout to increase the speed of numeric data entry, at least four cursor movement keys, and a growing number of other machine function keys having fixed or program assigned meanings. Leading computer manufacturers are now supplying universal word and data processing keyboards having over 100 keys, and the trade-off between function keys and displayed function lists or menus is becoming a topic of concern to systems designers.
Many inventors have endeavoured to improve the typewriter keyboard layout. The best known work is that of Dvorak et al, who described in 1932 a letter arrangement optimised in terms of carefully chosen criteria including letter frequencies, diagram frequencies, and the relative strengths and agility of the fingers. There are several more recent proposals for performance optimised keyboards, for example one due to X of Canada. Keyboards in straight alphabetic sequence have also been tried, but found slower than QWERTY even for persons with no typing experience, and are used only where ease of understanding is paramount, as with military field enciphering machines and communication devices for the elderly handicapped. Other inventors have worked on the shape of the keyboard, variously proposing key rows curved to match the natural arc of the fingertips, multiple key rows disposed in doubly curved bowl shapes to ease the reaches, thumb keys oriented nearly at right angles to the finger keys to better exploit the strength and agility of the thumbs, and a general outward tilt of the two sides of the keyboard for the comfort of the wrists. Some have worked on both shape and letter arrangement. Optimal keyboards have been proposed for several European languages. The Maltron keyboard now on the British market has an ergonomic shape and performance optimised layout. Increased speed, reduced fatigue, and reduced training time are claimed for it. The gain in speed from any of these performance optimised keyboards appears limited, and is tentatively estimated in Siebel (1972) at not more than 10%.
Where national keyboards may be used for foreign correspondence, there is a recognised problem of extending the national layout to accommodate additional characters. The needs of multi-lingual secretariats have lead to proposals for standard European keyboards, which cannot be optimal for any single language.
The chief difficulty with the QWERTY and other keyboards having one key for each character and machine function is the amount of training required to achieve proficient operation. The speed of 40-60 words per minute expected of a competant typist requires so-called `touch-typing`, that is reading the manuscript while simultaneously operating the keyboard with only tactile and audible feedback. To do this, the stimulus-response bonds which link letters and common groups of letters to the finger movements which key them must be thoroughly learnt. These bonds are sequence dependent, and the reaches over the rows make them complex. The apparently random order both of the QWERTY keyboard and of those based on letter frequency leads unavoidably to the worst kind of boring rote learning, devoid of principle or interest. Using traditional methods of teaching, some 60 hours of class training are required to achieve a basic competance, though programmed learning methods may reduce this somewhat. Untrained persons such as the journalists, authors, professionals and managers who now increasingly use computers without the intervention of specialist keyboard operators are unable to key at more than about 15 words per minute, even with much practical experience, because they become fixed in bad habits. Their keying is slower than handwriting, which commonly attains 20-40 words per minute. Thus work not requiring immediate response from the computer is still written out in longhand and sent to specialist keyboard operators. Work which does require immediate response is done less efficiently than it might be. Status conscious persons already reluctant to undertake a task they associate with persons of lower status are additionally inhibited by the fact that their performance is so much worse than that of these lower status persons. As professionals and managers are generally not willing to undergo formal keyboard training, the computer is of less benefit to them than it could be. With the expected wired society, this problem will extend to the community at large.
The alternative to a keyboard having one key for each character and machine function is one having fewer keys, used singly or in combination to signal the full character set. Keyboards of this type were in use for special purposes before the normal typewriter keyboard. The Baudot telegraph code of 1874 was signalled by a five key keyboard operated by the stronger fingers of both hands. Braille embossing machines were developed in mid-century and a common form with six code keys and a space key established in the 1890's. With a small number of keys, the problem of the reaches is eliminated, but the problem of remembering the codes arises. Several inventors have aimed to reduce this by codes based on letter shape. In 1975, Endfield and Rainey patented a keyboard for one hand on which between one and five keys are struck in a pattern suggesting a particular letter. This device is now on the market as the Microwriter. Experience has shown that a user can teach himself, and that a speed exceeding that of handwriting is reached after a few weeks. The tricks of style which aid memory are however weak for some letters and for figures and special characters. Also, speed is limited by the manual dexterity required. Using the Dewey frequency data, a weighted average of 1.82 keys must be pressed per letter, space or punctuation mark. The fingerings are governed by the need to support some resemblence or trick of memory, and many of them are relatively slow and awkward according to the rankings of Ratz and Ritchie and of Siebel (1962). Machines having 20 or 24 keys are also known and are used for courtroom shorthand recording at twice the speed of a QWERTY keyboard, but are specific to a phonetic encoding requiring long training.
A particularly simple encoding is afforded by a keyboard having a group of keys for each hand, and operated by striking one key of each group simultaneously. Such codes may be represented by a matrix in which one hand defines the column and the other defines the row. The Cooke and Wheatstone electric telegraph of 1837 had two groups of six keys which caused magnetic needles to indicate the axes of a matrix. The Pratt typewriter of 1866 had two groups of six keys giving 36 characters, and later two groups of eight keys giving 64 characters. Vondra, Tevis, and Boni proposed similar mechanical typewriters, and Linhares and Colombo have proposed electric versions. Kafafian includes a similar electric keyboard in his schemes for the handicapped. Electric keyboards with two key coding were investigated in depth around 1960 for use in applying postcodes to mail, and have since been reported in use. In a small experiment, postmen acquired basic competance on the code keyboard in 32 hours compared with 80 hours for the QWERTY keyboard, and were consistently faster on the code keyboard up to the end of the experiment at 100 hours of training. These results were obtained even though the training for the new keyboard was inevitably less expert than for the QWERTY keyboard, and the matrix layout logical but not particularly memorable. Siebel (1972) has estimated that such keyboards have a speed potential of 150% of the QWERTY keyboard, and advocates the use of chord keyboards by those not needing to be trained in QWERTY. He also refers to work on an eight key typewriter on which single keys were struck for common letters, two key combinations for the remaining characters, and combinations of up to seven keys for common words. There have been many proposals for word writing typewriters, none of practical value.
The cursor movement keys of the extended QWERTY keyboard give very limited movement capability. A single press moves the cursor one place up, down or sideways, as a king moves in chess. A press and hold brings into action after a delay of about half a second an auto-repeat function which moves the cursor at a fixed, rather slow speed in the chosen direction, but still only moving as a rook. Moves between two arbitrary points have to be made as a series of zig-zags. The cursor cannot move as a queen. The fixed auto-repeat speed, necessarily a compromise, is timewasting on long cursor moves and yet fast enough to lead to overshoots if the user is not very careful. To overcome these limitations, auxiliary devices such as the mouse or puck used to generate XY coordinates in graphics work are being adopted for character work. The ease of cursor movement with these devices is particularly important in supporting machine languages which exploit to the full the human preference for communicating by showing rather than telling. These auxiliary devices have however the disadvantage in textual work that one hand must be moved frequently between the keyboard and the mouse or other device, which is disorienting and timewasting. The fixed speed auto-repeat is also an irritant when entering multiple space characters to set out text. The mouse or puck does not help here.
A further disadvantage of the conventional keyboard is the high risk of accidentally initiating computer action by pressing the `Enter` key before one means to, due to its placement at the front of the keyboard next to one of the shift keys. In other machines, considerable care is taken to avoid accidental operation, for example by placing a key a little out of the way, or by recessing or hooding it. On presses and guillotines there are commonly two start buttons placed well apart which must be pressed simultaneously, thus ensuring that both of the operator's arms are in safe positions.
Actuation of the keys of an ordinary electro-mechanical typewriter requires significant force and displacement, and the device makes considerable noise. With an electronic keyboard this is not necessary. It is found however that touch typists still desire a keyboard requiring significant operating force and displacement, and making some noise. In part this is because fingers moving rapidly over the reaches acquire considerable momentum, which then has to be destroyed and reversed, in part it is because with their eyes on the copy they require tactile and audible confirmation that a signal has been registered by the machine. Authors and others originating information in their heads are generally not touch typists, and must look at the keyboard, so that they also cannot obtain immediate visual feedback from the visual display unit. The membrane keyboards now used to reduce the cost of small personal computers have attracted much criticism because it is not possible to tell by the feel of the keyboard whether a signal has registered. Sound generators have been used to overcome this problem. With a chord keyboard requiring no rapid reaches, and on which information originators could readily learn to touch-type, so that they became free to watch the display for visual confirmation as one watches the paper when writing by hand, audible feedback should not be necessary beyond the initial learning stage, and slight or zero key displacement may be acceptable or preferred if tactile feedback of finger to key engagement is given and signal registration is reliable. Silent operation then becomes practical.
Information relevant to the design of electronic keyboards may be obtained from the known art of the design of wind instruments of music. In both, in contrast with non-electric typewriters and musical instruments such as the piano, the fingers are required only to control the machine, not to supply the power which drives it. Quantz and all later writers agree that the fingers should be curved in a moderate arch, and should strike the keys with their pads, not with their tips. This is impossible with typewriter keyboards having multiple rows of keys. On wind instruments all unnecessary motion is avoided, and the least possible force and displacement are preferred in the interests of speed. Keys are not used because they feel better than open holes, which do not give under the fingers, but solely because there are more notes in the octave than fingers on the hand. The occasional proposals in the data processing art for thumb keys operating in a plane differing from that of the finger keys are supported by the flute, oboe, clarinet and other wind instruments on which the thumb works in opposition to the fingers, and by the French horn on which it works at right angles. The agility of the thumb is best evidenced by the bassoon, on which it is required to operate up to nine keys singly or in combination. On all wind instruments the thumb is expected to work with the same speed and precision as the fingers.
______________________________________ PRIOR ART REFERENCES ______________________________________ PATENT LITERATURE ______________________________________ British 1937 7,390 Cooke W. F. and Wheatstone C. 1866 3,163 Pratt J. 1884 9,048 Thompson W. P. 1897 10,672 Anderson G. K. 1914 2,809 Burboa J. G. H. 1923 213,485 Hall E. C. 1923 231,397 Vondra K. 1924 237,197 Fischer O. and Naamloze 1927 293,990 Allen C. F. 1929 330,476 Marloth K. 1933 409,138 Dvorak A. and Dealey W. L. 1938 510,548 Muther A. 1949 700,083 Panocha A. 1950 698,327 Boni A. 1963 966,181 Creed & Co 1964 1,016,993 IBM 1974 1,424,306 X of Canada 1975 1,496,522 Endfield C. and Rainey C. J. 1978 2,000,083 Malt L. 1980 2,041,295 Marsan C. 1980 2,076,743 Winkler E. E. United States 1933 1,906,196 Linhares A. 1936 2,031,017 Tevis R. 1945 2,375,526 Colombo O. 1970 3,507,376 Kafafian H. 1970 3,718,991 Kafafian H. 1973 3,929,216 Einbinder A. 1976 3,945,482 Einbinder A. 1979 4,180,337 Otey F. B. 1982 4,332,493 Einbinder A. ______________________________________ OTHER LITERATURE ______________________________________ Alder M. H. (1973) The Writing Machine Alden D. G. et al Keyboard Design and Operation: A Review of the Major Issues Human Factors 1972, 14(4), 275-293 Beeching W. A. (1974) Century of the Typewriter Carse A. (1965) Musical Wind Instruments Conrad R. and Maintenance of High Accuracy Leonard J. A. Without Augmented Feedback Nature Vol 199, No 4892, 3 August 1963 Conrad R. and Standard Typewriter versus Longman D. J. A. Chord Keyboard - An Experimental Comparison Ergonomics Vol 8, 1975, 77-88 Crooks M. (1965) Touch Typewriting for Teachers Dewey G. (1923, 1970) Relative Frequency of English Speech Sounds Hirsch R. S. Procedures of the Human Factors Center at San Jose IBM Systems Journal Vol 20, No 2, 1981 Nakaniski A. (1980) Writing Systems of the World Quantz J. J. (1752) On playing the Flute Ratz H. C. and Operator Performance on a Chord Ritchie D. K. Keyboard J Applied Psychology 1961 Vol 45, No 5, 303-308 Rendall F. G. (1971) The Clarinet Siebel R. Performance on a Five-Finger Chord Keyboard J Applied Psychology 1962 Vol 46, No 3, 165-169 Siebel R. Data Entry Devices and Procedures in Van Cott H. P. and Kinkade R. G. (eds) (1972) Human Engineering Guide to Equipment Design Spencer W. (1958) The Art of Bassoon Playing West L. J. (1969) Acquisition of Typewriting skills Klemmer E. T. A Ten-Key Typewriter IBM Research Memo RC-65 (1958) Lockhead G. R. and An Evaluation of an 8-Key Word- Klemmer E. T. Writing Typewriter IBM Research Memo RC-180 (1959) ______________________________________